Hydrocarbon conversion process and apparatus



Sept. 28, 1954 E. v. BERGsTRoM HYDROCARBON CONVERSION PROCESS AND APPARATUS Filed March 9, 1950 4 Sheets-Sheet 1 7 L w 0 P 3 4 a 2 m m 2 f d I z o w ,7. 2 W rJ gli 1 n f, M Wm Z M H0 n WN 4. 7 om 3 1 /1 Tf l 4J w .Z u a u 1M a n w 1 w V 3 BY ma() Sept. 28, 1954 E V, BERGSTROM 2,690,056

HYDROCARBON CONVERSION PROCESS AND APPARATUS Filed March 9, 1950 4 Sheets-Sheet 2 L/Fr (1/15 auf 1 Sept. 28, 1954 E. v. BERGSTRQM 2,690,056

HYDRocARBoN CONVERSION PRocEss AND APPARATUS Filed March 9, 195o I y 4 sheets-sheet s 105 @E N TRHL eww/foam llll" l INVENToR.

91k //'Qrgs/ram Sept. 28, 1954 E. v. BERGsTRoM HYDROCARBON CONVERSION PROCESS AND APPARATUS Filed March 9, 1950 4 Sheets-Sheet 4 i E i i LYM/ll- IZ? /fzz 7 INVENTOR. 1Z0 'r/Z' /egs//w/fz am a.

Patented Sept. 28, 1954 UNITED STATES ATENT oFFIcE HYD-ROCARBON CONVERSION PROCESS AND APPARATUS Eric V; Bergstrom, Short Hills, N'. J., assignor to tSocony-Yacuum; (lilv Company, Incorporated, aV corporation'. ofl New York.

Application March 9, 1950, Serial No. 148,669

5.(ilaims. 1.

This application is directed toa process: and apparatus for converting hydrocarbons in, the presence of a particle-form solid contact mass. It has particular relation to a method and appa-- ratus for adjusting the temperature of hot granular contact material in continuous movingy bed:V conversion systems.

Various hydrocarbon conversion processes are known in which a hydrocarbon liquidiv or vapor is brought into Contact withy a comminuted1 solid material at a suitable, high temperature and for a sufficient periodi of time to provide a vsubstantial conversion of the hydrocarbonsinto other' more desirable hydrocarbons. In these conversion processes a carbonaceous'deposit isformed on the solid contact material impairing the function of the contactlmaterial, making it essential that the deposit be removed. therefrom. Itis lcus-- tomary in these processesto regenerate or4 restore the contact materiali to. its form'ervcondition by burning the carbonaceous deposit from thewcontact material.

In a preferred form of hydrocarbon conversion the solid contact material ist continuous-1y passed through a conversion zone: as a substantially compact moving column of particle-form material. Hydrocarbons are admitted tothe conI version zone and converted' products: removed.

therefrom continuously for long periods .off time. The particle-forrny material is continuously withdrawn from the zone., contaminated. with..carbo naceous material. The contaminated material' is then passed downwardly as a substantially compact column through a burning zone' whereink the carbonaceous material is b-urned from the con-l tact material, restoring the contact material substantially to its original state.

rlhe burning of carbonaceous materia-l1 on the solid contact materialis highly exothermic. 'In many instances it is necessary to extract heat from the contact material before -it can be transported through elevators which would be dam aged by the excessive temperature .of thematerial or before it can be supplied to thel reaction vessel for further hydrocarbonconversion. The natu-re of the problems involved'and the man-ner in which they are met by the present invention is Well illustrated by apparatus for conversion of higher boil'- ing hydrocarbons to ethylene by reaction for a very short time, say 0.2 second at high temperatures on the order of l500 F. and above. To 0btain the necessary short reaction time the 'high temperature reaction mixture must be promptlyy quenched to a low temperature'l lOne advantageous system for accomplishing this hightemperature short timereaction is to pass the charge hydrocarbons in direct contact with a bed of highlyl heated granular solidandv then passl the hot reaction mixture through a bed of relatively cold granular solid. This requires two contacting chambers connected bya transfer line which will confine the hot gaseous mixture within a predetermined path. The hot contact material from the reaction chamber on which carbo-y naceous material is deposited during thevr conversion reaction is cooled from about 1000 to.1100" F. down to about 500150 80.0 F., lifted by a suitable elevator to a heater, in which the carbonaceous material isburned from the material, and then readmitted to the reaction chamber as a downwardly moving column of contact material.

This problem is also illustrated by the adiabatic TCC process, in which solid Contact ma.- terial is passedV downwardly as a substantially solidicolumn through a reaction zone whereinv it is contacted with hydrocarbons which are converted to suitable hydrocarbonsV in the gasoline range in .substantial amounts and the Contact material is then passed downwardly as a substantiallyf solidv column` through a, regeneration zone in which the contact material is contacted with a combustion supporting gasto burn oi the carbonaceousdeposits on the surface of the material. In the prior TCC processes, the regeneration, generally, provided sufcient heat to damage the catalyst, requiring the removal of heat from the kiln. Thiswas accomplished by dividing the kiln into a series of burning and cooling zones.

The temperature of the catalyst leaving .each

burning zone was: controlled partly by the number of cooling coils in service in the following cooling zone. The cooling in the cooling Zone was provided, generally, by one or more levels of horizontal, spaced tubes. Water was circulated through the number of tubes necessary to give the required cooling. Thus the effective heat transfer surface was varied by the number of tubes through which cooling Water was circulated. In normal cracking operations, the reactor conditions vary frequently, Which, in turn, causes variations in the amount of heat generated in the kiln and, therefore, the amount of heat which must be removed in the cooling zones. This requires cutting Water iiow in and out of some of the tubes. Since a tube which does not have water flowing through it may be at a temperature of about 1l00 F., for example, While the water used forcooling may be only 200 to 400Q F., severe stresses are set up in the tubes each time water is cut in or out. This caused `frequent fail-ure of the tubes, particularly at the location where they are sealed into the header.

In the recent adiabatic process the catalyst flow rate is increased substantially, approximately 2 or 3 times the old rate. Consequently, the carbon lay down on the catalyst during reaction is reduced because the catalyst is retained in the reactor a shorter period. The temperature .reached in the regenerator, therefore, is maintained below the heat damaging level because there is a smaller per cent of carbon to be burned therein. The catalyst enters the kiln at approxi.- mately 850 F. and is withdrawn at approximately 1200 F., below the heat damaging temperature limit. No heat transfer tubes are needed in the kiln, permitting the kiln design to be eX- ceedingly simple and easy to service. But, as previously indicated, generally, more heat is released in the kiln than is needed in the reactor, and, therefore, there is presented the problem of removing this excess heat from the system. A catalyst cooler of some sort must be included in the system, usually located subsequent to the kiln.

Prior art catalyst or pebble coolers are not found satisfactory for a variety of reasons. inasmuch as more or less heat must be extracted from the catalyst from time to time, some means of control of the cooler characteristics is required. For example, many coolers allow the coolant to flow through exchanger tubes, being equipped with controls for preventing the flow of coolant through selected tubes. The empty tubes assume the temperature of the moving Contact material. Consequently, when they are put back in service, the cold coolant uid contacts the hot walls of the tube, causing the metal to spall and crack. This necessitates frequent cooler repair and replacement. Many of the prior coolers are disfavored because of their complexity, excessive cost or difhculty of control. Because of their tendency to develop leaks, the use of cooling iiuids under pressure was largely precluded in the prior art coolers.

Moving bed catalyst systems of hydrocarbon conversion are effectively replacing xed bed systems of operation. They have proved to be economical in the larger units of a size about 10,000 to 15,000 barrels per day. Usually, the kiln is divided into a series of stages with burning stages f day of charging stock, the cost of the kiln was found not to reduce in proportion to reduction in cost of the remaining equipment. By making the kiln without tubes, and providing a simple cooler adapted for use outside of the kiln, the unit has been found to provide an economically feasible moving bed system for the small refiner.

It is not intended that this invention be limited to the specic embodiments shown. One of the broader aspects of this showing involves using a catalyst or pebble cooler in which is located a heat exchanger, adapted to place particle-form contact material in indirect heat exchange relationship with a cooling fluid. The heat exchanger is maintained flooded with coolant fluid throughout the entire contact surface area. Molten salts such as potassium nitrate or nitrite may be used as the coolant fluid, as well as molten metals but liquid water, maintained under pressure, is preferred.. For example, water pressures of 300-350 pounds per square inch may be used, with the temperature being maintained Constant at the boiling temperature by maintaining the water pressure at a fixed value. The terrperature of the contact material is controlled by varying the volume of the contact material brought into contact with the cooling surface.

The object of this invention is to provide a simple method of cooling and adjusting the temperature of hot granular contact material.

A further object of this invention is to provide a simple cooler for cooling and adg'usting the temperature of hot, particle-form contact material.

Another object of this invention is to provide an improved hydrocarbon conversion process.

Another object of this invention is to provide an improved process for the catalytic cra-cking of hydrocarbons.

These and other objects of this invention will be made apparent in the following discussion of the invention, read in conjunction with the attached sketches. The sketches are intended to illustrate the invention, and are highly diagrammatic in form.

Figure 1 is a diagrammatic showing of the relationship of the several elements making up a plant for the conversion of hydrocarbons to ethylene.

Figure 2 is a detail view in section of the reactor outlet port of Figure l and the cooler located therebelow.

Figure 3 is a plant for conducting hydrocarbon conversion in accordance with adiabatic TCC principles.

Figure 4 is a view, partially in section, of the cooler used in the plant of Figure 3.

Figure 5 is a vertical section showing a variant form of cooler design.

Figure 6 is a vertical section showing a further embodiment of the invention.

Figure 'l is a plan View of the iris valve shown on plane 7 7 of Figure 6.

Referring specifically now to Figure l, a hot granular solid is heated to a suitable high temperature in heater i0 and transferred by feed leg I l through a steam sealing zone i2 to a reactor A charge for the reaction is introduced by a plurality of inlet tubes l0 depending from ring manifolds l5 at the top of the reactor. Within the reactor i3 the charge is passed in direct ccntact with the highly heated granular solids a' d is thus rapidly converted to a vapor phase mixture having the temperature desired for the reaction. Upon leaving the contact bed, the reaction mixture is quenched by the injection of water supplied from inlet l0 and is passed by conduit I'I to a quencher I8 wherein it is passed through a moving bed of relatively cool granular solids for further reduction in temperature. The quenched reaction mixture is transferred by line i9 to a spray condenser 20 from which product vapors are taken overhead by line iii to a suitable gas plant for purification and recovery of the gaseous products of the reaction. Oil and water from the bottom of condenser 20 are passed to a settler 22 wherein they separate into an upper oil layer which is cooled in heat exchanger 23 before transfer to processing or storage and a lower water layer which is cooled in heat exchanger 24 to be recycled in part to the spray condenser by line 25. If the charge to the reactor is in liquid phase, water from the bottom of settler 22 may be used in the charge, since contamination of the charge water has no detrimental eect in such operations, the contaminants accepte bein-'gr either.' vaporized: with. the:A waterv or de'- posited on the granular solidf from: whichv 'they may be removed byfbunningI inthe heater.

Returning. now' tofth'f;y reactor I3; a purge gas su'ch assteam` is admitted to theV bottom of the reactor at inlet 26 and afpressuring medium, whichY may alson be steam; is admitted at inlet 27: to' be used: to provide a pressure seal in the insulation of" theve'ss'et for preventingv deposition of carbonaceous substances in the reac'tor insulation. The granular solids are withdrawn fromthebottom. et reactor. I3L by pipe- 28. and

are-passed through a-fcooler 29( and depressuring pot -30 and then tothe bottom of. the. elevator 3| In general, solids transferred. to the elevator. must bef maintained` at a.- temperature which will notv damagey thel elevator or adversely affect its operations. The excessyheat is extracted from' the solidsin the cooler'zllf. Solidsrare discharged from thetop of elevator 3G into' a: feed pipe 32, passedthrough a 'classifier 3-3-for removal'of particlesbroken.y down' to ay size smaller than that desired'` and are then fed/ to heater I0- to again pass through the cycle: In the heater, fuel from inlet 3'4 isburned in preheated air supplied at to generatel a flame in direct contact with the solid granules andy thus.v heat the latter to the desired degree. Elue gasesv are withdrawn at 35 and passed. to anJ economizer. or stack.

The quencher is an element of a similar cycle of granular solids-and-Whereinthe granules serve to cool vaporous reaction mixture from reactor I3 and are then purged by steam admitted at 31 and passed by pipe38 through the cooler 39 and depressuring pot 40 to' an elevator 4I. From the top of the elevator 4l the solids are discharged by pipe 42' through a classifier 43 to a hopper 44. Solids are supplied through feed leg 45 to an air preheater 46 wherein they are contacted with air from blower 41 to preheat the same. The preheated air is then transferred by line 48 to inlet 3.5 of heater I0. Any carbonaceous deposit in the nature of coke' or tar laid down on the solids inthe quencher I8 Will be burned oil in heater 46 but a large excess of air is supplied to chamber 46 and the net effect is to. cool the solids in chamber 46. whereupon the cold granules are transferred by feed leg 49 through a steam purging zone 50 to the quencher l. Details of theinternal structure` of these vessels may be found in copending application Serial No. 670,277, now United States Patent No. 2,520,482 whichy issued. on October 29, 1950.

Referring now tol Figure 2', the internal structure of the coolers 29 and 39 isshown. The outlet of the reactor projects through the topof the cooler 29; Within the coolertheoutlet conduit of the reactor is surrounded by an axially laligned conduit 5l which is adapted to be` raised or loweredV with respect to the' outlet conduit. The exterior portion of the conduit possesses a rack gear E2 adapted to mate with the pinion gear 53 providing a telescoping motion for the aligned' conduits. The pinion gear isdriven by a suitable prime mover, such` as; an electric: motor, not shown. In the lower portion of the cooler is located the upper and lower tube sheets 54, 55`

between which is fastened vertical connecting tubes' t6, adapted to` pass particle-form material through the exchanger section. Thev flow of contact material from the transfer tubes is controlled by the'valvetlr inthe outlet vconduit located therebelow. A coolingv solution is circulated tracted by flow of the cooling fluid according to 6% the thermo-syphon; principle: Gfaseous.l coolant is'. withdrawn'z from the: heat'. exchanger section through..y the conduit 5.7:' to theftanlr 5.8" located above: the exchangerrsectioni. Within the tank the gaseous coolant condensessback to a liquid. Coolant liquid' is' continuously,y Withdrawn from thebottom of= the-tank tothe heat, exchanger section of thei'cooler through the'conduit 59. A cooling fluid is passed through a continuous conduit in the vessel 58-to= extract the,v heat` therefrom;' Ther cooling' fluid.l is introduced through the conduit 6B froma source not shown and removed through thefc'onduit 61.

By' theaboveV procedure, the heat exchanger section of the coolery ismaintained flooded with constant temperature. coolant. liquid at all times.

The amount of. heat to be' extractedr from the granular material'variesfw-ithLa: number of factors such as; for example;l the' amount and type of reactants fed to the bed ofv granular material in the reactor` I3.. It is obviously desirable to extract. only suflicient head from the granular material tof prevent` damaging the elevator and its related' parts rornthe excessive temperature of the. contact-'material By rotating the pinion gear. 53theslidingconduit-l may be raised or lowered. to'cause the' pile li'to spread out over a larger or Asmaller areay of the tube sheet 5ft. The pile willonly nowy untilzthe angle of repose of. the contact materialA iss reached, making the area of the tube sheet coveredl dependent' upon the height of. the'bottom of therconduit 5i above the upper tube.y sheet.' 54.. As less area of the tube sheet is covered, fewer of the vertical tubes 56. will beA used` for transferring the granular materialt through the. heat exchanger. inasmuch as the temperature of.y the coolant fluid. is maintained: 'constant by the. thermsyphon principle ci operation, less'heatwill be extracted from the granular material when fewer tubesv are used for thetra-nsfer of the contact material because less volume of the contact material is brought into Contact with the cooling. surface.

tis-seen-that af. readymeansofadjusting the temperature of. the-contact material, while-maintaining ahooded heat exchanger with coolant liquid at a. substantially fixed temperature, is provided.

Referring nowto .Figure 3,. a system is shown for carryingout adiabaticregeneration in a TCC process A downwardly moving column of catalyst particles in the reactor 710 is contacted with the hydrocarbon charge admitted through the conduit 'it from a stock. preparation zone, not shown- TheV products produced by the catalytic conversion of the hydrocarbon charge are removed through the conduit 12 to other apparatus, nots'hown, for further treatment. The fouled contact material is removed from the bottom of the reactor lilA through the conduit 73 to the' regenerator'll The flow of. contact material in the condmitl 7:3` is controlledA by the valve 15. Air is admitted tothe regenera-tor T4 through the conduit-'ld-.toburn off theca-rbona'cecus'material from the' surface of thev contact material moving through the vessel as a descending substantially solid column. The flue gasformedzinth'e regenen ator is removed through the conduit ll. In this process the-'catalyst llow rate is suiciently rapid to prevent the contact material being overheatedl in the: regenerator. For' example, 'the material enters the regenerator'at a temperature of about 856 F. and' is removed'. therefrom at a temperature 4ot about 1200" I'nthis system no heat exchanger tubes are required' in the regenerator.

making the regenerator construction simple. In addition, the regeneration gas ilow may be limited to a value slightly in excess of that required for complete combustion of the coke. For example, the flow of air to the regenerator may be limited to a rate of flow Which is about 20 per cent in excess of that required for chemically correct combustion of the coke deposits present on the catalyst.

The contact material removed from the regenerator 'l0 is passed through the conduit 18 into a cooler 88 disclosed in more detail on Figure 4. The cooled catalyst is discharged from the cooler Sti, is passed through the conduit 8l and lifted by the gas lift 82. The valve 83 in the conduit i3! is used to control the discharge of catalyst from the cooler. Lift gas is introduced near the bottom of the lift through the conduit 84 and the catalyst is lifted by the lift gas and raised to the top of the lift. The lift gas may be inert gas, steam, iiue gas or air. The catalyst is separated from the gas in the disengaging chamber 85, and delivered through the conduit 86 to the hopper 8l'. The lift gas is discharged from the disengaging chamber through the conduit 88. During regeneration of the catalyst water is removed from association with the catalytic material. When the dehydrated catalyst is again contacted with steam, the catalyst rapidly adsorbs the steam with the release of great quantities of heat described as heat of hydration. For some catalytic materials this may involve a heat release equal to or greater than the heat of hydrocarbon conversion, however, certain of the synthetic catalysts have heats of hydration which are much lower. Hydration of the catalyst is performed in the hopper 8l by introducing steam through the conduit 90 at a rate controlled by the valve 9|. The conduit is connected with a multiplicity of perforated pipes in the base of the hopper which provides for uniform distribution of the steam throughout the gravitating mass. The excess steam may be removed through a vent in the roof of the hopper. The catalyst flows from the hopper 87 through the connecting feed leg 89 into the reactor l0, thereby completing the continuous catalyst flow path. Various seals are used to prevent the transfer of gases from one vessel to another; inert gases are used to purge catalyst moved from one vessel to another. These details are not shown on the Figure 3, but can readily be found in the various patents on moving bed catalytic cracking.

Due to increased demand for gasoline and the increased amount of crude stocks converted to gasoline to meet this demand, it is now necessary that heavier stocks, for example, stocks which are normally liquid at reactor feed temperature, be charged to the reactor. Because these heavier stocks are more sensitive to thermal conditions, and thermally crack at or about reaction temperatures, they are charged at lower temperatures in liquid form. For example, the liquid and vapor feed can be charged to the reactor at about 700 F. Suitable reaction temperatures run about 850 to about 950 F., depending upon type of catalyst, reaction conditions, type of feed stock, etc. A system for feeding mixtures of liquid and vaporous hydrocarbons to a reaction vessel is shown in copending case Serial Number 719,724 led January 2, 1947, now United States Patent No. 2,574,850 which issued on November 13, 1951. Sufficient heat is extracted from the catalyst withdrawn from the regenerator in the cooler to leave enough sensible heat and potential hydration heat in the catalyst to supply the total heat required in the reactor. This may be only reaction heat or it may be reaction heat plus sensible and latent heat to get the reactants into Vapor phase at the desired reaction temperature. The reactor can be operated with concurrent or countercurrent flow of reactants and catalyst mass, and the reactants may be charged in liquid form, vapor form, or a mixture of both liquid and vapor.

It is possible to remove some heat from the kiln, when found expedient, by recirculating cooled iiue gas or by using heat transfer tubes in the regenerator, but it is preferred to cool in the cooler as indicated herein.

The continuous system may be operated at a catalyst to oil ratio of about l-20 pounds of catalyst per pound of oil, and at space velocities of about 0.5-10 volumes of oil (measured at 60 F.) per hour per volume of contact material column within the conversion zone. The conditions will vary somewhat with catalyst material, catalyst activity, type of feed stock, etc. In such processes it is found desirable to limit the particle size broadly within the range of about 3 to 100 mesh and preferably Within the range of about 4 to 20 mesh Tyler Standard Screen analysis. The percentage of fines present in the contact material mass should be maintained as low as possible.

Referring now to Figure 4, an enlarged vieuv of the cooler of Figure 3 is shown, partially in section. The catalyst introduced into the cooler S8 forms a pile below the conduit 78. The short conduit 19 below the conduit 78 is somewhat larger in cross-section than the conduit "i3 and is adapted to be raised or lowered by; the lever G5 pivoted in the bearing 96. The conduit "i9 is operated by the wheel 6'! which operates the mating gears 68, 69. The shaft Eil maintains the conduit 'i9 in substantial alignment with the conduit 78. A series of cooling conduits or tube bundle is located in the cooler 90, with or without deecting baies. The bundle is arranged to provide paths for the catalyst which bring the catalyst in contact with the cooling surface during its downward travel. The cooled catalyst is discharged from the bottom of the cooler through the conduit 8 i, the flow being controlled. by the valve 83. The tube bundle 90 is supplied with a suitable coolant from a source, not shown, through the conduit 9| and the coolant is discharged through the conduit 92.

Referring now to Figure 5 another embodiment of the invention is shown. Downwardly moving contact material is introduced through the conduit into the top of the cooler 99. The contact material is received in the enclosed chamber 98 and discharged from the bottom of the chamber 96 through a multiplicity of conduits Sl adapted to distribute the contact material evenly across the cross-sectional area of 'the cooler. Valves 98 are located in the conduits il? for controlling the flow of contact material through the conduits. By closing the Valves in the outer conduits the pile of contact material below the valves may be made to cover a smaller area of the cross-section of the cooler. In the lower section of the cooler are located upper and lower tube sheets 99, |00 and a multiplicity of transfer tubes 19|. Thus more or less of the transfer tubes IUI may be lled with contact material by the control of the valves 93. The space surrounding the tubes i0! is lled with a cooling fluid supplied through the conduit Mii?, and discharged through the conduit i055. The

' temperature of the vcoolant may be-'maintained substantially constant by suitable control vof the valves Ulli, located in the conduits |02, |03. T-his `may suitably be done by a controller m5 connected to a temperature 'indicator Il, and adapted to automatically control the valves iM, |65. lThe cooled contact material is discharged from the cooler 96 through the conduit |03. As indicated the valves 98 vmay be controlled by a central controller |99 adapted to maintain a substantially constant temperature in the'outlet conduit |08.

In Figure 6 is shown still .another embodiment of this invention. In the top of the cooler 4| lll is projected the conduit .adapted to introducey contact material onto the shelfor fioor H2. The shelf or floor H2 has an Yorifice in .its lcenter adapted to pass contact material therethrough onto the top of an iris diaphragm lle. In the lower section of the cooler llil are located tube sheets and transfer tubes, similar to those previously described, adapted topermit the transfer of contact material downwardly through the tubes in contact with a cooling fluid. By the indicated system of gearing the iris diaphragm may be opened or closed to cause the pile of contact material on the upper tube sheet to cover a large or smaller area of the tube sheet, thereby controlling the number of transfer tubes through which the contact material is passed. The iris diaphragm H3 is driven by the motor Ild through the speed reducer H5. The motor l I4 can be controlled by a controller I6 adapted to maintain the temperature of the contact material in the outlet conduit substantially constant. The iris diaphragm serves only as a baiiie and is not a throttling device. The diaphragm completely closed will permit the transfer of suflicient contact material to meet the needs of the system.

Figure '7 shows a plan View of the iris diaphragm of Figure 6 as seen on plane '1 1 of Figure 6. The leaves l IB of the diaphragm are attached by the members ||9 to a suitable support frame, which, in turn, is supported by the cross supports |20, attached to the inner wall of the cooler. The ring |2| is fastened to a second frame by the cap screws |22 and the leaves are fastened to this frame by the cap screws |23. The quadrant of a gear |24 is attached to the ring l2! by the bar |25. Rotation of the gear |24, eifected by rotation of a mating pinion gear not shown, causes the ring |2| to rotate and thereby causes the leaves ||8 to pivot on the pivot points H9. The rotation of the leaves l |8 causes the central opening to increase or decrease, depending upon the direction of rotation of the leaves ||8.

This application shows broadly a method and apparatus for cooling granular contact material which is related, in some of its broader aspects, to the copending application Serial Number 154,130, filed April 15, 1950.

What is claimed is:

l. A cooler for comminuted solid contact ma-y terial comprising an enclosed vessel, a downwardly directed feeding conduit projected into the top of said vessel and terminating near the top thereof, a short conduit telescoping the end of said conduit adapted for movement in an axial direction, said short conduit having an axially aligned rack gear located on its outer surface, a pinion gear disposed adjacent said short conduit and adapted to engage and drive said rack gear, means for driving said pinion 10 gear, `cooling means defining a multiplicity of downwardly directed paths disposed in. the lower section of said vessel through which contact material maybe vlowered as substantially compact columns, means for'introducing coolant fiuid into thecooling means, means for withdrawing coolant fluid from the cooling means, said cooling means adapted -to bring the coolant fluid into indirect heat exchange relationship with the contact material-throughout the entire length of the paths, and meansdening an outlet in said vessel through which cooled contact material may be withdrawn.

2. In a cooler for granular contact material in which `a `heat exchanger is located in the bottom portion thereof arranged to provide a mulvtiplioityrof downwardly'directed paths substantially equally distributed *acrossv the cross-section of the cooler,the method of operation which comprises: the steps of maintaining the heat exchanger flooded with cooling fluid, introducing the .contact material into the cooler at a location near Athe top thereof, gravitating the contact material through a depending conduit termi- -nated at a location above the heat exchanger,

discharging ythecontact material from the conduit to form a pile on top of the heat exchanger,

vgravitating the lcontact material through the heat exchanger paths located directly below the pile of contact material, adjusting the elevation of the outlet of the dependingconduit to cause the pile of contact material to cover a sufcient portion of the area of the top of the heat exchanger, so that enough paths are lleol with contact material to extract from the contact material the desired amount of heat and withdrawing the cooled contact material from the bottom of the cooler.

3. The method of changing the temperature of a particle-form solid contact material which comprises: passing the contact material through a conned heat exchange zone to contact a heat transfer surface along at least a portion of one side thereof, subjecting substantially the entire area of the opposite side of said heat transfer surface to the inliuence of a iiuid heat exchange medium existing at a temperature substantially different from that of said contact material and maintained out of communication with the contact material, discharging the contact material from said heat exchange zone and selectively controlling the temperature of the contact material discharged at the desired level by adjustably controlling the volume of contact material within said Zone which is at any instant under the influence of said heat transfer surface.

4. A cooler for comminuted solid contact material comprising an enclosed, vessel, cooling means dening a multiplicity of downwardly extending paths disposed in the lower section of said Vessel through which contact material may be lowered as substantially compact columns, means for introducing cooling fluid into the cooling means, means for withdrawing cooling fluid from the cooling means, said cooling means adapted to bring the cooling fluid into indirect heat exchange relationship with the contact material throughout the entire length of the paths, means defining an inlet in the upper portion of the vessel for the introduction of contact material, baffling means operatively connected to said inlet means for controlling the area of the top of said cooling means covered by said contact material, means for adjusting the baflling means,

whereby the required number of paths are filled with contact material to effect the desired temperature adjustment and means defining an outlet in said vessel through which cooled Contact material may be withdrawn.

5. A cooler for comminuted solid contact material adapted for gravitation therethrough of a compact column of hot contact material comprising: an enclosed vessel, cooling means defining at least one downwardly extending path for ow of solid contact material within said vessel, means for introducing coolant uid into the cooling means, means for withdrawing coolant fluid from the cooling means, said cooling means adapted to provide a predetermined surface area for contact with the column of contact material Which is in flooded contact With cooling fluid at all times and which places the contact material in indirect heat exchange relationship with the cooling fluid, means defining an inlet for the introduction of contact material into the upper portion of the vessel, baiing means operatively connected With said inlet, adapted to direct the column of the contact material into contact with at least a portion of the cooling means, means for adjusting the baling means, to vary the amount of cooling surface contacted with contact material and means dening an outlet in the bottom of said vessel through which the Contact column may be withdrawn.

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